Confocal Raman spectroscopy to monitor intracellular penetration of TiO sub(2) nanoparticles

• Published in: Journal of Raman spectroscopy 2014-09, Vol.45 (9), p.807-813
• Main Authors: Salehi, Hamideh, Calas-Bennasar, Isabelle, Durand, Jean-Cedric, Middendorp, Elodie, Valcarcel, Jean, Larroque, Christian, Nagy, Katalin, Turzo K, Kinga, Dekany, Imre, Cuisinier, Frederic JG
• Format: Article
• Language: English
• Subjects: Apoptosis; Confocal; Cytochromes; Diffusion; Microscopy; Nanoparticles; Penetration; Titanium dioxide
• ISSN: 0377-0486; 1097-4555
• DOI: 10.1002/jrs.4561

Confocal Raman microscopy, a noninvasive, label-free, and high-spatial resolution imaging technique, in combination with K-mean cluster analysis and a correlation coefficient map, was employed to trace titanium dioxide (TiO sub(2)) nanoparticles in living MCF-7 and TERT cells. The penetration of TiO sub(2) nanoparticles into cells revealed a gradual time-dependent diffusion of nanoparticles over the entire cell. Cell apoptosis was monitored by tracing cytochrome c diffusion into the cytoplasm. A comparison with the mitochondrial clustering indicated that cytochrome c was inside the mitochondria for TiO sub(2) concentration of 2 mu gml super(-1). This result demonstrates that the presence of TiO sub(2) particles within a cell does not induce apoptosis. We demonstrated that confocal Raman microscopy allow to follow penetration of TiO sub(2) particles in cell and to monitor the apoptotic status of the penetrated cells. Copyright [copy 2014 John Wiley & Sons, Ltd. Titanium dioxide (TiO sub(2)) nanoparticles in living MCF-7 and TERT cells were traced by confocal Raman microscopy in combination with K-mean cluster analysis and a correlation coefficient. A gradual time-dependent diffusion of nanoparticles over the entire cell was observed. Cell apoptosis was monitored by tracing cytochrome c diffusion from mitochondria into the cytoplasm. The concentration of 2 mu gml super(-1) TiO sub(2) particles within a cell does not induce apoptosis.